sum of real numbers up to n using recursive code

I'm trying to make more sense of recursive code as I have only very recently started using matlab. I was wondering how I would go about finding the sum of all real numbers up to x using recursive code, I have done it using if / for / while loops however after trying to self teach myself I would expect to go about this by:

function y = sum(x)
    if x > 0
        y = x * (x+1) / 2
    end
    elseif x <= 0
        y = 'does not exist'
    end 
end
disp(y)

I understand that I am probably wrong, in which case how would I go better about this task. Any help would be appreciated.

[Image Analyst]

You can edit the code to fix it you know. So go ahead and add the end.

How are you calling this? What is the initial value of x you're using? I assume the x are all integers, right? Is x a scalar or vector? And you have a finite number of them. Because the sum of all real numbers is infinite.

[Will Murphy]

My apologies, x is a scalar what will equal where the integers finish.

Answer 1

[David Hill]

function x = t_sum(n)
x=1;
if n>1
    x=n+t_sum(n-1);%recursive
end